1. Field of the Invention
The present invention relates to a sealing member for sealing toner within a processing means used for forming an image with the toner, a process cartridge employing such a sealing member, and an image forming apparatus into which the process cartridge can be loaded.
2. Description of the Related Art
An image forming apparatus, such as a printer, performs selective exposures onto a uniformly charged image carrier to form a latent image. The latent image is made visible by toner, and the toner image is transferred to a recording medium so that the image may be recorded. In such an apparatus, additional toner must be supplied each time it is used up. Not only is this operation for supplying toner inconvenient, but the operator's hands may become dirty. Also, it is necessary to periodically perform maintenance of each member of the apparatus.
FIG. 32 illustrates a conventional process cartridge in which supplying of toner and replacement of parts of an image carrier whose service life is finished are made possible when a user loads the cartridge into the main body of the apparatus. Maintenance is made easier since an image carrier 50, a charger 51, a developing unit 52, a cleaning unit 53 and the like are formed integrally into the cartridge (see, for example, U.S. patent Ser. Nos. 3,985,436, 4,500,195, 4,540,268 and 4,627,701).
In such a process cartridge, the developing unit 52 is provided with a sealing member 55 so that toner will not leak out from a gap formed between a development sleeve 52a and a development frame member 54. The cleaning unit 53 has a sealing member 56 provided in the end portion of the image carrier 50 so that waste toner will not leak out from the gap formed between the end portion of the image carrier 50 and a waste toner well 53a.
One type of the above-mentioned sealing member is formed of foam rubber, felt or the like so that it can be applied onto a container. Another type is formed of a material such as plastic, has a lip portion which slidably contacts process means such as the development sleeve 52a, the frame member or the like so that the other type can be installed into the frame member.
However, in the former sealing member, it is time-consuming to apply the sealing member, and automation of attachment is difficult. The latter sealing member has the advantage that attachment is easy. However, the dimensions of the portion where the sealing member comes into close contact with the frame member varies, causing a problem, for example, of the toner leaking from the gap.